Method and apparatus for managing information in wireless communications

ABSTRACT

Disclosed is a communication device including a portable terminal having a wireless communication function. The communication device receives category information and associated information from an information providing apparatus located at a relatively short distance to store both pieces of the information in an internal memory. The communication device deletes information received prior to the latest point of time of reception from the internal memory.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is based upon and claims the benefit of priorityfrom the prior Japanese Patent Application No. 2003-053814, filed Feb.28, 2003, the entire contents of which are incorporated herein byreference.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The present invention generally relates to a communication devicefor receiving information through wireless communication, and inparticular, relates to a technique to manage information.

[0004] 2. Description of the Related Art

[0005] Recently, portable communication devices such as mobile phones orpersonal digital assistants (PDAs) are in widespread use. In thesecommunication devices, there are provided functions in which thewireless communication can be used to receive a wide variety ofinformation from information providing systems using a wirelesscommunication function, and the information can be employed usingsoftware.

[0006] Specifically, a portable terminal is proposed in which there isprovided a function to receive geographical information and use it(e.g., see Jpn. Pat. Appln. KOKAI Publication No. 2002-236763).

[0007] A telecommunications system is also proposed in which desiredinformation only can be obtained efficiently from among providedinformation (e.g., see Jpn. Pat. Appln. KOKAI Publication No.2002-24273).

[0008] In the portable terminal related to the former prior art, thefollowing function is given, namely, when the portable terminal receivesthe geographical information and use-permission positional informationand determines that the portable terminal does not belong to aneffective area identified by the received use-permission positionalinformation, it deletes the received geographical information.

[0009] Here, the geographical information delivered to the portableterminal is associated with the use-permission positional information.Therefore, a geographical information transmitting party must attach,without fail, restraint information, namely the use-permissionpositional information, to the geographical information to betransmitted. In addition, when there are provided a plurality ofgeographical information transmitting parties, no procedure isconsidered if the portable terminal receiving the geographicalinformation receives the information of the same type.

[0010] Moreover, in the system related to the latter prior art, there isprovided a function to delete the provided information in which thesystem constantly checks whether established deletion conditions withrespect to the received information in a memory are satisfied or not sothat only the provided information needed is stored in the memory.

[0011] In this system, deletion conditions are generated by aninformation receiving party and the information is deleted after thedeletion conditions are satisfied. Therefore, the deletion conditionsthat are set by users are assumed. In addition, when there are provideda plurality of information transmitting parties, as well as the formerprior art, no procedure is considered if information of the same type isreceived.

[0012] In other words, in each method of the prior art, since particularconditions are required upon deletion of the received information, as aresult, the possibility increases in which unnecessary information isaccumulated within a communication device such as a portable terminal.

BRIEF SUMMARY OF THE INVENTION

[0013] In accordance with one embodiment of the invention, there isprovided a communication device that has a function to automaticallydelete information that becomes unnecessary among information receivedthrough wireless communication.

[0014] The communication device comprises an antenna module whichreceives information transmitted through wireless communication andincludes a receiver sensitivity measuring function; a determining unitwhich determines effectiveness of the received information in accordancewith the receiver sensitivity measured by the antenna module; a categorydetermining unit which determines a category of the receivedinformation; a storage unit which stores the received information aseffective information in accordance with determining results of thedetermining unit and the category determining unit; and an informationdeletion unit which deletes information of the same category receivedprior to the latest received information from the storage unit.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

[0015] The accompanying drawings, which are incorporated in andconstitute a part of the specification, illustrate embodiments of theinvention, and together with the general description given above and thedetailed description of the embodiments given below, serve to explainthe principles of the invention.

[0016]FIGS. 1A and 1B are diagrams that describe an outline of aninformation providing system in accordance with an embodiment of theinvention.

[0017]FIG. 2 is a block diagram that shows main parts of a communicationdevice and an information providing apparatus in accordance with theembodiment.

[0018]FIG. 3 is a flowchart that describes a procedure for informationmanagement in accordance with the embodiment.

[0019]FIG. 4 is a flowchart that describes a procedure for informationprocessing of the communication device in accordance with theembodiment.

[0020]FIG. 5 is a conceptual diagram in accordance with anotherembodiment.

[0021]FIG. 6 is a flowchart that describes a procedure for informationprocessing of the communication device in accordance with anotherembodiment.

DETAILED DESCRIPTION OF THE INVENTION

[0022] Now, with reference to the drawings, embodiments of the inventionwill be described.

[0023]FIG. 1 describes an outline of an information providing system inaccordance with the embodiment.

[0024] A communication device in accordance with the embodiment is aportable terminal 10 that has a wireless communication function. Asshown in FIG. 1A and FIG. 1B, the portable terminal 10 has the functionin which information delivered, through wireless communication, from aplurality of wireless communication base stations (20A to 20D) thatcorrespond to respective information providing apparatuses, is receivedand employed.

[0025]FIG. 1A shows state in which the portable terminal 10 moves torespective areas covered by respective wireless communication basestations (20A to 20D) along with a moving user (dashed line arrow). Theportable terminal 10 utilizes information delivered from the wirelesscommunication base station (20A to 20D) that is located at a relativelyshort distance as effective information. As mentioned below, theportable terminal 10 determines, using a function measuring receiversensitivity (i.e., strength of received radio wave) included in anantenna module, the wireless communication station (20A to 20D) that islocated at the relatively short distance (See FIG. 2).

[0026] Here, for example, geographical information is assumed as theinformation provided by the respective information providingapparatuses. This geographical information shall be the information thatcorresponds to the communication areas covered by the wirelesscommunication base station (20A to 20D).

[0027] To be more precise, as shown in FIG. 1A, the portable terminal 10receives the information (geographical information) from the wirelesscommunication base station 20A that is located at the relatively shortdistance as the effective information to store it in an internal memory.The portable terminal 10 executes processing so that the receivedgeographical information is displayed on a display. Hereby, the user canrefer to a map whose effective area is only the area that is based onthe provided geographical information.

[0028] Next, as shown in FIG. 1B, along with the moving user, theportable terminal 10 receives the information (geographical information)from, for example, the wireless communication base station 20C that islocated at the relatively short distance as the effective informationand stores it in the internal memory. Hereby, the user can refer to themap whose effective area is only the area where the user moved.

[0029] Here, for the portable terminal 10, after its movement,information received prior to its movement (here, it means thegeographical information from the wireless communication base station20A) generally becomes unnecessary information. Therefore, in theembodiment, the portable terminal 10 deletes the information thatbecomes unnecessary (i.e., information received prior to its movement)from the internal memory. Hereby, a use rate and information processingefficiency of the internal memory in the portable terminal 10 can beimproved. In addition, the user can constantly employ only the latestand effective geographical information using the portable terminal 10.

[0030] (Structure and Operation of the Portable Terminal and theInformation Providing Apparatus)

[0031] Hereinafter, the concrete structure and operation of theembodiment will be described with reference to FIG. 2 to FIG. 4.

[0032]FIG. 2 is a block diagram that shows the structures of theportable terminal 10 and the information providing apparatus 20,respectively.

[0033] The information providing apparatus 20 is what is called a serverand includes a provided information input unit 200, a categoryinformation input unit 201, a provided information storage unit 202, acategory information storage unit 203, an associating unit 204, anassociated data storage unit 205 and an associated data delivery unit206. The information providing apparatus 20 is designed by the structurecomprising software and a CPU executing the relevant software or byhardware configuration such as the memory and storage (disk drive) orthe like.

[0034] The provided information input unit 200 receives the informationto be provided (here, it means the geographical information.) and storesit in the provided information storage unit 202. The categoryinformation input unit 201 receives the category information thatindicates the category of the information to be provided (here, it meansthe map) and stores it in the category information storage unit 203.Here, the provided information storage unit 202, the categoryinformation storage unit 203 and the associated data storage unit 205mean, for example, a hard disk drive or the like.

[0035] The associating unit 204 associates the information (geographicalinformation) that is to be provided and is stored in the providedinformation storage unit 202 with its category information that isstored in the category information storage unit 203, then stores it inthe associated data storage unit 205. The associated data delivery unit206 delivers associated information (geographical information and itscategory information) that is stored in the associated data storage unit205 through the wireless communication base station (20A to 20D).

[0036] The portable terminal 10 includes an antenna module 100 forreceiving the radio wave transmitted from the wireless communicationbase station (20A to 20D), an associated data reception unit 101, adistance determining unit 102, a category information determining unit103, a receivable category information storage unit 104 and a receivablecategory information input unit 105.

[0037] The antenna module 100 includes the receiving function receivingthe information, in the form of radio waves, that is delivered from theinformation providing apparatus 20, while including the measuringfunction measuring the receiver sensitivity corresponding to thestrength of the relevant received radio wave. The distance determiningunit 102 determines the distance from the wireless communication basestation (20A to 20D) of the information providing apparatus 20 inaccordance with the receiver sensitivity that is measured with theantenna module 100. To be more precise, the distance determining unit102 generates determining information identifying the wirelesscommunication base station (20A to 20D) that is located at therelatively short distance.

[0038] The associated data reception unit 101 has a function determiningwhether the information (associated information) received with theantenna module 100 is received or not and stores the receivedinformation in an associated data storage unit 107. The associated datareception unit 101 determines reception of the received information(authentic reception) based on a determining result from the distancedetermining unit 102 and a determining result from the categoryinformation determining unit 103.

[0039] That is to say, the associated data reception unit 101 receivesthe information in accordance with the 20 determining result from thecategory information determining unit 103 when the category informationincluded in the associated information received matches a predeterminedcategory information, while the reception is rejected when mismatchoccurs. In addition, the associated data reception unit 101 receives, incase of the information of the same category, the information from theinformation providing apparatus 20 that is located at the relativelyshort distance in accordance with the determining result from thedistance determining unit 102.

[0040] The category information determining unit 103 compares receivablecategory information that is input by the category information inputunit 105 and is stored in the receivable category information storageunit 104 with the category information tentatively received at theassociated data reception unit 101.

[0041] The category information input unit 105 inputs the categoryinformation that is previously transmitted from outside through theantenna module 100 or the category information that is input from aninput apparatus (not shown) of the portable terminal 10 by the user intothe receivable category information storage unit 104.

[0042] Moreover, the portable terminal 10 has an associated datadeletion unit 106 and an information presentation unit 108. Theinformation presentation unit 108 executes processing by which theinformation that is stored in the associated data storage unit 107 isdisplayed on the display, for example, provided on the portable terminal10, or the like. Using this information presentation unit 108, the usercan refer to the received geographical information on the display.

[0043] The associated data deletion unit 106 deletes the informationdetermined to be unnecessary from among the information that is storedin the associated data storage unit 107. To be more precise, when theassociated data deletion unit 106 receives, in accordance with thedetermining result from the distance determining unit 102, theinformation from the information providing apparatus 20 that is locatedat the relatively short distance, it deletes all the information(information of the same category) that is previously received and isstored in the associated data storage unit 107. The distance determiningunit 102 constantly monitors, in accordance with the receiversensitivity measured with the antenna module 100, the distance from theinformation providing apparatus 20 (wireless communication base station(20A to 20D).

[0044] In addition, the portable terminal 10 is designed by thestructure including the software, the CPU that executes the relevantsoftware and the internal memory (such as flash EEPROM). The associateddata storage unit 107 is a component that corresponds to the internalmemory.

[0045] (Operation of the Portable Terminal)

[0046] Next, the operation of the portable terminal 10 in accordancewith the embodiment will be described with reference to FIG. 3 and FIG.4.

[0047] First, basic operation in accordance with the embodiment will bedescribed with reference to a flowchart of FIG. 3.

[0048] When the portable terminal 10 receives the radio wave with theantenna module 100, the associated data reception unit 101 determineswhether the received information is effective or not (receivable ornot)(Step S1 and S2). The associated data reception unit 101 determinesit, as mentioned above, in accordance with both measured result of thereceiver sensitivity at the antenna module 100 and the categoryinformation (information indicating that it is the geographicalinformation) included in the associated information received.

[0049] To be more precise, in accordance with the measured result of thereceiver sensitivity, the associated data reception unit 101 regards theinformation as effective, the information being delivered from theinformation providing apparatus 20 located at the relatively shortdistance. For more detail, when the portable terminal 10 is located on aposition as shown in FIG. 1A, the information that is delivered from theinformation providing apparatus 20 corresponding to the wirelesscommunication base station 20A. It is needless to say that theassociated data reception unit 101 regards the information asineffective regardless of content of the information when the receiversensitivity does not exceed a given level.

[0050] Furthermore, when the mismatch occurs between the categoryinformation included in the associated data received and the categoryinformation (map) previously stored in the receivable categoryinformation storage unit 104, the associated data reception unit 101determines that it is not effective (NO in step S2). In this case, theportable terminal 10 executes other processing until it receives theeffective information.

[0051] The associated data reception unit 101 determines the receivedgeographical information to be effective and receives it, and thenstores the information in the associated data storage unit 107 (YES inStep S2 and Step S4). Hereby, with the information presentation unit 108of the portable terminal 10, the user can refer to the receivedgeographical information on the display.

[0052] In this embodiment, when the associated data reception unit 101receives the effective geographical information, the associated datadeletion unit 106 deletes the geographical information (information ofthe same category) that is previously received prior to the currentpoint of time of reception (the latest point of time of reception) andstored in the associated data storage unit 107 (Step S3). For example,as shown in FIG. 1B, a case is assumed in which, along with the movingportable terminal 10, the information is received from the informationproviding apparatus 20 that corresponds to the wireless communicationbase station 20C. In the above-mentioned case, the information that isdelivered from the information providing apparatus 20 corresponding tothe wireless communication base station 20A is deleted from the internalmemory 107, the information being received prior thereto.

[0053] Concrete operation of the portable terminal 10 in the embodimentis described with reference to a flowchart of FIG. 4.

[0054] When the antenna module 100 receive the radio waves, theassociated data reception unit 101 executes the determining ofsuitability whether it is receivable or not (Steps S11 and S12). Whenthe mismatch occurs between the category information included in theassociated information received and the category information previouslystored in the category information storage unit 104, reception isrejected by the associated data reception unit 101 in accordance withthe determining result from the category information determining unit103 (Steps S13 and S20).

[0055] When both pieces of the category information match, theassociated data reception unit 101 receives the information as effectivein accordance with the determining result (receiver sensitivity) of thedistance determining unit 102, the information being from theinformation providing apparatus 20 located at the relatively shortdistance (Step S14). As a matter of course, reception of the informationthat is from the information providing apparatus 20 located at arelatively long distance is rejected even if the category is the same(Step S20).

[0056] The associated data reception unit 101 stores the receivedinformation (geographical information) in the associated data storageunit 107 (Step S15). The information presentation unit 108 executesprocessing such as displaying the information stored in the associateddata storage unit 107 on the display, for example, provided on theportable terminal 10, or the like (Step S16). With this informationpresentation unit 108, the user can refer to the received geographicalinformation on the display.

[0057] In the portable terminal 10, when the effective geographicalinformation is received by the associated data reception unit 101, theassociated data deletion unit 106 is activated (YES in Step S17). Theassociated data deletion unit 106 retrieves the associated data storageunit 107 and deletes the geographical information that is received priorto the current point of time of reception (the latest point of time ofreception)(Step S18 and S19).

[0058] As described above, in accordance with the embodiment, when theinformation (geographical information) of the predetermined category(e.g., map) is received as effective, the information of the samecategory (e.g., geographical information in different area) that ispreviously received and stored can be deleted from the internal memory107.

[0059] In consequence, the user's operation is not necessary and theunnecessary information can be automatically deleted from the portableterminal 10. Hereby, the portable terminal 10 can omit the processingfor displaying the unnecessary information for the user. In addition,since the unnecessary information can be deleted from the internalmemory 107 of the portable terminal 10, the use rate of the internalmemory 107 can be improved.

[0060] Here, the associated data deletion unit 106 of the embodiment maydelete, in accordance with the determining result (receiver sensitivity)from the distance determining unit 102, the received information asunnecessary, the received information being the information receivedwhen the distance changes from the relatively short distance to a longdistance. In this case, an operation may be possible in which at thestage when communication to the information providing apparatus locatedat the relatively short distance is established, the previousinformation is not deleted immediately but is temporarily stored and isdeleted at the stage when a certain distance arises.

[0061] In addition, the portable terminal 10 may include the structurehaving a function in which the information received from respectiveinformation providing apparatuses is not deleted immediately but storedin the internal memory, and then the plurality of pieces of informationare displayed on the display, the pieces of information being weightedaccording to the distance from the information providing apparatuses.

[0062] Furthermore, the portable terminal 10 does not delete informationpreviously received but stores it in the internal memory after attachinga possible deletion index to it. Then, the portable terminal 10 deletesthe information only to which the possible deletion index is attached atthe time there is a shortage of internal memory capacity.

[0063] Moreover, at the stage when the communication to the informationproviding apparatus located at the relatively short distance isestablished, the portable terminal 10 does not receive and store theinformation received from the apparatus, yet retrieves the internalmemory. The portable terminal 10 may have structure in which when theportable terminal succeed in retrieving the information from theinternal memory, then the information can be used intact. Here, when thepossible deletion index is attached to the information, the possibledeletion index is deleted.

[0064] Although the portable terminal 10 in accordance with theembodiment is assumed to be standard mobile phones and personal digitalassistants (PDAs), the embodiment is not limited thereto and dedicatedterminals, for example, applicable to portable type navigation can alsobe assumed.

[0065] (Another Embodiment)

[0066]FIG. 5 and FIG. 6 describe another embodiment.

[0067] The embodiment relates to the portable terminal 10 that receivespositional information transmitted from a wireless communication device54 (wireless chip), instead of the wireless communication base station,the wireless communication device 54 having a short distance wirelesscommunication function in a narrow area such as exhibition hall and soon. In addition, the basic structure of the portable terminal 10 is thesame as the one that is shown in FIG. 2.

[0068] The wireless communication device 54 is a small sized devicewhich includes a wireless communication circuit that transmitsidentification code information such as a positional code. In theembodiment, as shown in FIG. 5, an exhibition hall 50 in which pluralbooths are placed is assumed. Respective booths 53 are exhibition areasto present different products and services, respectively.

[0069] The wireless communication device 54 is placed with respect toeach booth 53 and constantly transmits the identification codeinformation (positional code information) to identify a position of eachbooth 53. Moreover, in the embodiment, an information providingapparatus 52 that delivers guidance information of each booth 53 isplaced, for example, in the vicinity of an entrance 51 of the exhibitionhall 50. The information providing apparatus 52 is basically the same asthe one that is shown in FIG. 2 while aforementioned positional codeinformation with respect to each booth 53 is used as the informationcorresponding to the category information.

[0070] (Operation of Another Embodiment)

[0071] Hereinafter, mainly with reference to a flowchart in FIG. 6, theoperation of the embodiment will be described.

[0072] First, when the user enters the exhibition hall 50 through theentrance 51, the portable terminal 10 receives the guidance informationthat is delivered from the information providing apparatus 52 (StepS100). At the time, the portable terminal 10 receives the guidanceinformation that is associated with the positional code information andstores it in the internal memory.

[0073] Next, when the portable terminal 10 moves within the exhibitionhall 50 along with the user, it receives the positional code informationtransmitted from the wireless communication device 54 placed withrespect to each booth 53. At the time, as mentioned above, the portableterminal 10 receives the positional code information as effective inaccordance with the receiver sensitivity measured with the antennamodule, the positional code information being transmitted from thewireless communication device 54 located at the relatively shortdistance (YES of Step S101).

[0074] The portable terminal 10 retrieves the guidance information fromthe internal memory, the guidance information corresponding to thereceived positional code information (Step S102). The portable terminal10 executes the processing displaying the relevant guidance informationon the display (Step S103).

[0075] Hereby, the user can refer to the guidance information on thedisplay of the portable terminal 10, the guidance information being theinformation from the nearest located booth 53. Therefore, for example,the user can judge, in accordance with the relevant guidanceinformation, whether the booth is the desired booth or not and when hedoes not have interest in the booth, he can move to the other booths.

[0076] On the other hand, after receiving the guidance informationregarding the positional code information when the portable terminal 10cannot receive the relevant positional code information, the portableterminal 10 deletes the guidance information that is stored in theinternal memory (YES in Step S104, and S105). As mentioned above, basedon the receiver sensitivity measured with the antenna module, whenreception level does not exceed a given level, the portable terminal 10determines that the relevant positional code information cannot bereceived.

[0077] Here, when the portable terminal 10 cannot receive the positionalcode information correctly within a predetermined time interval, theportable terminal 10 makes a transition to the processing to delete theguidance information stored in the internal memory. Even if the guidanceinformation stored in the internal memory is once deleted, the portableterminal 10 can restore the relevant guidance information by moving inthe vicinity of the entrance 51 again to receive the guidanceinformation from the information providing apparatus 52.

[0078] As mentioned above, it follows that, for example, when theportable terminal 10 in the embodiment cannot receive the positionalcode information which is effective only within the area in theexhibition hall 50 after receiving and storing the guidance informationwhich is effective only within the area in the exhibition hall 50, itdeletes the relevant guidance information.

[0079] To be more precise, when the user goes out of the exhibition hall50, the portable terminal 10 automatically deletes the relevant guidanceinformation because it cannot receive the positional code information.Hence, outside the exhibition hall 50, the relevant information thatbecomes unnecessary can be deleted from the portable terminal 10. If theuser hopes to restore the deleted guidance information, it can berealized by receiving the guidance information again at the exhibitionhall 50.

[0080] In addition, although the embodiment relates to an informationmanagement method in which the guidance information at the exhibitionhall 50 is associated with the positional code information, theembodiment is not limited thereto and it can be applied to theinformation management method in a narrow area, for example, a themepark or the like. Moreover, in the embodiment, although the portableterminal has the structure in which the stored guidance information isdeleted when it cannot receive the positional code information, theembodiment is not limited thereto. For example, one structure may bepossible in which, when the portable terminal 10 receives theinformation that indicates deletion of the guidance information, itdeletes the stored guidance information.

[0081] As described above in detail, in accordance with the embodiment,when the information of the same category is received from a pluralityof information providing parties to utilize, all the information otherthan the latest information is deleted. Moreover, among the informationthat is received prior to the latest point of time of reception,information that is shifted from effective to ineffective is deleted.Therefore, as a result, unnecessary information can be automaticallydeleted from the communication device.

[0082] Additional advantages and modifications will readily occur tothose skilled in the art. Therefore, the invention in its broaderaspects is not limited to the specific details and representativeembodiments shown and described herein. Accordingly, variousmodifications may be made without departing from the spirit or scope ofthe general invention concept as defined by the appended claims andtheir equivalents.

What is claimed is:
 1. A communication device comprising: an antennamodule which receives information transmitted through wirelesscommunication and includes a receiver sensitivity measuring function; adetermining unit which determines effectiveness of the receivedinformation in accordance with the receiver sensitivity measured by theantenna module; a category determining unit which determines a categoryof the received information; a storage unit which stores the receivedinformation as effective information in accordance with determiningresults of the determining unit and the category determining unit; andan information deletion unit which deletes information of the samecategory received prior to the latest received information from thestorage unit.
 2. The communication device according to claim 1, whereinif a plurality of sending devices of the information are provided, thedetermining unit determines information transmitted from a sendingdevice located at a relatively short distance to be effective bycalculating distances from the sending devices of the information inaccordance with the receiver sensitivity.
 3. The communication deviceaccording to claim 1, further comprising; a category information storageunit which stores category information indicating the category of theeffective information, wherein the category determining unit determinesthe relevant received information to be effective when the category ofthe information received with the antenna module matches the categoryindicated by the category information.
 4. The communication deviceaccording to claim 1, wherein the information deletion unit deletesprevious information of the same category as the information from thestorage unit before the effective information is stored in the storageunit.
 5. The communication device according to claim 1, wherein theinformation deletion unit deletes previous information of the samecategory as the information from the storage unit after effective andreceivable information is stored in the storage unit.
 6. Thecommunication device according to claim 1, wherein if a plurality ofsending devices of the information are provided, the determining unitdetermines information transmitted from a sending device located at arelatively short distance to be effective by calculating distances fromthe sending devices of the information in accordance with the receiversensitivity, and the information deletion unit deletes previousinformation of the same category as the information from the storageunit before the effective information is stored in the storage unit. 7.The communication device according to claim 1, wherein the determiningunit determines the information only of a particular category deliveredfrom a wireless communication base station located at a relatively shortdistance to be effective, the storage unit stores the information of theparticular category determined to be effective by the determining unit,and the information deletion unit deletes, from the storage, unit theinformation of the particular category that is received from thewireless communication stations other than the wireless communicationstation located at the relatively short distance.
 8. A method ofmanaging information applicable to a communication device having anantenna module which receives information transmitted through wirelesscommunication and includes a receiver sensitivity measuring function,and a storage unit to store the information, the method comprising:determining effectiveness of the information in accordance with thereceiver sensitivity measured with the antenna module; determining acategory of the received information; and deleting information of thesame category received prior to the latest received information from thestorage unit.
 9. A method according to claim 8, further comprising:receiving information of a particular category delivered from aplurality of wireless communication stations placed on plurality ofplaces with the antenna module; determining the information only of theparticular category delivered from a wireless communication stationlocated at a relatively short distance to be effective in accordancewith the receiver sensitivity measured with the antenna module, if theplurality of wireless communication base stations are provided; storingthe information of the particular category determined to be effective bythe effectiveness determining in the storage unit; and deleting previousinformation of the same category as the relevant information from thestorage unit before the effective information is stored in the storageunit.
 10. A method according to claim 9, wherein the deleting is todelete, from the storage unit, the information of the particularcategory received from the wireless communication base stations otherthan the wireless communication base station located at the relativelyshort distance in accordance with a determining result of theeffectiveness determining.
 11. A method according to claim 9, whereinthe deleting is to retrieve and delete all the information of theparticular category from the storage unit when the information of theparticular category determined to be receivable and effective is storedin the storage unit.
 12. A method according to claim 8, furthercomprising: receiving, with the antenna module, identification codeinformation delivered from a plurality of wireless communication devicesplaced with respect to each predetermined area; storing informationcorresponding to the identification code information received with theantenna module in an internal storage unit; selecting, from the internalstorage unit, the information corresponding to the identification codeinformation received from a wireless communication device located at arelatively short distance among the respective wireless communicationdevices; determining suitability of reception of the identification codeinformation from the respective wireless communication devices; anddeleting all the information regarding the identification codeinformation stored in the internal storage unit when the reception ofthe identification code information from the respective wirelesscommunication devices is not possible.
 13. A method according to claim12, wherein the identification code information is information toidentify a position of the area on which the respective wirelesscommunication devices are placed.